Jang Song Thaek, who married Kim's aunt, was the vice chairman of North Korea's top military body and has often been pictured beside Kim, who has ruled North Korea since his father's death in 2011.

"Some see this as perhaps the last part of the power consolidation phase, that Kim Jong Un has in fact removed all of the old guard close to his father and is now finalizing the inserting of his own inner group," said John Park, a Northeast Asia analyst at Harvard's Kennedy School of Government.

Jang and his allies were accused by Kim of double-dealing behind the scene, "dreaming different dreams" and selling off the country's resources at cheap prices, thereby threatening North Korea's economic development, according to the KCNA statement.

In this Tuesday, Aug. 14, 2012 file photo provided by China's Xinhua News Agency, Jang Song Thaek, North Korea's vice chairman of the powerful National Defense Commission, attends the third meeting on developing the economic zones in North Korea, in Beijing. Two South Korean lawmakers say they were told by intelligence officials that two associates of North Korean leader Kim Jong Un's powerful uncle Jang were executed last month. They say the uncle has not been seen in public since then and may have been dismissed. There was no way to independently confirm the report about Jang. (AP Photo/Xinhua, Li Xin, File) NO SALES

"Jang desperately worked to form a faction within the party by creating illusion about him and winning those weak in faith and flatterers to his side," the statement said.

The public document also scolds Jang for improper relations with several women, drug use, gambling, eating at expensive restaurants and getting medical treatment in a foreign country.

Last week two close allies of Jang -- Lee Yong-ha and Jang Soo-kee -- were publicly executed, South Korean lawmakers said at a news conference.

The lawmakers, including Cho Won-jin of the governing Saenuri Party, said this after receiving what they said was a briefing from South Korea's National Intelligence Service. CNN has not been able to independently confirm the report.

North Korea, a state shrouded in secrecy, is involved in a protracted standoff with its neighbors and Western powers over its nuclear weapons program.

Tensions between North and South Korea soared this year as Pyongyang reacted angrily to tightened United Nations sanctions imposed in response to its latest nuclear test.

The two sides are still technically at war after the Korean War, from 1950 to 1953, ended in a truce, not a treaty.